An estimated 60-84% of newborn infants develop neonatal jaundice, which produces a yellowing of the skin caused by the accumulation of excess bilirubin (hyperbilirubinemia), a naturally occurring compound produced by the breakdown of red blood cells. Although this condition is typically harmless and resolves within a few days, highly elevated levels of bilirubin can lead to kernicterus, a devastating and irreversible neurological condition characterized by deafness, cerebral palsy, profound developmental delay, or even death.
Current approaches for monitoring bilirubin levels in infants typically require repeated testing in a hospital setting. The blood concentration of bilirubin can be determined by the total serum bilirubin (TSB) measured from a blood sample, or via a transcutaneous bilirubinometer (TcB) measurement accomplished using a non-invasive but costly instrument. These tests are often unavailable in resource-poor settings, thus impeding early detection and treatment of kernicterus. Visual assessments, which are frequently used as an alternative to these tests, are often inaccurate and can be confounded by factors such as lighting or skin tone. Accordingly, improved approaches are needed for providing non-invasive, cost-effective screening for excessive bilirubin levels.